The present invention relates to surgical instruments for treating female urinary stress incontinence problems generally and in particular, a tubular mesh sling for implanting into the lower abdomen of a female which provides support to mid-urethral and bladder neck sphincteric continence sites.
Pubovaginal sling surgical procedures for treatment of stress urinary incontinence in women are based historically on many clinical studies that show excellent results utilizing autologous rectus fascia. In the classic pubovaginal sling procedure, a strip of rectus fascia is removed from the anterior abdominal wall of the patient and the tissue is transplanted to the anterior vaginal wall to provide anatomical support to the bladder neck continence site. The long term continence results from this operative technique have been superior to other surgical procedures, especially in women who have very poor function of the urethra.
Women who have a rectus fascia pubovaginal sling procedure experience significant postoperative discomfort that results from harvesting the fascia from the anterior abdominal wall. Although rectus fascia has excellent tensile strength and superb long term durability, it has very little elasticity. Consequently, postoperative urinary retention is a problem if the sling is placed with tension around the urethra. Urethral obstruction and difficulty voiding are common postoperative complications following rectus fascia pubovaginal sling procedures.
In an effort to avoid the morbidity of rectus fascia slings, synthetic sling materials have been used. Serious complications of infection, erosion, and obstruction have occurred from the many different synthetic sling materials and designs that have been used. These include infections related to the implantation of a non-absorbable foreign body into the vagina as well as erosion of the synthetic sling into the urethra and vagina. The most notable of the synthetic sling material products was the Protegen(copyright) brand of synthetic sling that received wide media attention because of postoperative complications.
In an effort to avoid problems of infection with synthetic slings as well as morbidity with rectus fascia slings, cadaveric tissues were introduced as a sling material. Cadaveric fascia and cadaveric dermis have been used as an alternative to autologous rectus fascia. Most studies of cadaveric tissues show that these tissues do not have the long term durability of the rectus fascia tissue transplanted from the abdomen to the vagina of the same patient.
During recent years, a small filament polypropylene synthetic tape has become widely used in the contemporary art. The small filaments are associated with a low incidence of infection and erosion. The durability of the material appears to be good. The Tension-free Vaginal Tape (TVT)(copyright) utilizes a proline mesh tape that is woven with small proline filaments. The small diameter of the filaments appears to allow tissue ingrowth that prevents serious complications of synthetic non-absorbable sling materials that occurred in the past.
The TVT is surgically implanted in the patient using an instrument placed from the vagina and passed through the retropubic space to the suprapubic area. The difficulty in passing the instrument from the vagina to the suprapubic area has resulted in numerous serious complications from intra-operative injury to organs in the pelvis. Although the synthetic tape sling is tension free, many surgeons have difficulty achieving proper tension on the tape. For this reason, complications of recurrent urinary incontinence may occur in patients having too little sling tension and bladder outlet obstruction may occur in patients having too much sling tension on the tape.
The SPARC(copyright) modification of the TVT was developed to avoid the instrument complications that occur with TVT. The SPARC utilizes an instrument that is passed from the suprapubic area through the retropubic space into the vagina rather than from the vagina through the retropubic space to the suprapubic area as in the TVT. The SPARC instrument modification significantly reduces the potential for serious bowel and vascular injuries. Bladder perforation continues to be a problem for the SPARC modification, however cystoscopy is always done after the instrument is in position and the instrument is removed and repositioned if bladder perforation is identified. Both the TVT and SPARC are tension free tape pubovaginal sling procedures. The proline (polypropylene) mesh tape of the SPARC is almost identical to the proline mesh tape of the TVT. Surgeons continue to have difficulty intraoperatively with sling tension using these tape procedures. The SPARC was designed with a suture down the center of the sling that can be used to release excess sling tension intraoperatively. However, the suture modification for sling tension is rarely used by surgeons and intraoperative adjustment of sling tension continues to be a problem for both the TVT and the SPARC.
U.S. Pat. No. 6,406,423 (hereinafter xe2x80x9cScetbonxe2x80x9d) purports to disclose a modification to avoid the bladder perforation problem of both the TVT and the SPARC using the same type of synthetic suburethral tape used in the SPARC and TVT. The procedure uses a complex instrument system that is passed through the retropubic space under finger guidance, which is the same technique that has been used for rectus fascia slings procedures for many years. The morbidity of the transvaginal dissection of the retropubic space described in this procedure is identical to the rectus fascia sling procedures in the past. One of the objectives of current sling procedures is to avoid the paravaginal dissection required for the Scetbon technique. One of the reasons for the success of the TVT and the SPARC is that neither require paravaginal dissection described in the Scetbon modification. The mid-urethral positioning of the sling described in the TVT and SPARC is surgically difficult to accomplish from the approach described by Scetbon.
A biodegradable tape sling of the contemporary art has recently been introduced by Mentor, Inc. and is trademarked as SABRE(copyright). The tape is a non-mesh synthetic biodegradable design consisting of a small patch attached to ends that have a saw-tooth pattern which hold the sling in position. The sling transfer instrument is larger in diameter than the SPARC instrument and has much less curvature. There is very little clinical experience at this time using this device. Historically, synthetic non-mesh slings have had a high incidence of erosion and infection. Although this product is biodegradable, it has the inherent short term risks of synthetic non-absorbable products since it represents a foreign body until it is absorbed.
Unlike the instant invention, all of the above pubovaginal sling designs involve using a narrow single layer tape sling. The TVT and SPARC sling are polypropylene mesh slings 1 cm wide that are placed in the mid-urethra of women who have urinary incontinence. The most common cause of stress urinary incontinence in women is altered anatomy of the urethra. A sling design is needed that can conform to the anatomical variations of the urethra of women who have urinary incontinence. Most women who have moderate to severe urinary incontinence have associated anatomical prolapse of the urethra and bladder. Some women have had multiple previous incontinence surgical procedures and have intense scar formation around the urethra. The intraoperative positioning of the narrow mesh tape in women who have anatomical distortion of the urethra from prolapse or previous surgery can be difficult. As evidenced in the above discussion of pubovaginal sling designs and sling transfer instruments, an improvement in sling design is essential for improvement in the success of incontinence surgery as well as for reduction of morbidity and complications. An improvement met and addressed via the teachings of the instant invention.
In the preferred embodiment of the present invention, a surgical instrument for treating female urinary stress incontinence comprising a) a tubular mesh sling for implanting into the lower abdomen of a female providing support to mid-urethral and bladder neck sphincteric continence sites, said sling defining in part plastic sheath portions fixedly attached to a tubular mesh section; and b) a tubular sling transfer instrument having a distal end and a proximal end, said instrument defining in part a progressively curved shaft portion positioned between distal and proximal ends with a handle located at its proximal end, a detachable tip positioned and angularly displaced from said curved shaft at its distal end, a means for attaching said detachable tip to said progressively curved shaft portion and a sling transfer collar which is removably attached to said detachable tip and said tubular mesh sling plastic sheath portions.
The tubular knit mesh pubovaginal sling of the instant invention is disclosed as a two layer single component configuration which allows the sling to conform to anatomical variations of the anterior vaginal wall and urethra that are commonly encountered during the surgical implantation of a pubovaginal sling in women who have prolapse of the bladder and urethra resulting in anatomical distortion of the urethra. During the surgical implantation of the tubular knit mesh pubovaginal sling, enhanced positioning beyond that afforded via the contemporary art and can be achieved by using forceps to xe2x80x9crollxe2x80x9d the sling into the desired position along the urethra. This is especially important in women who have had previous vaginal surgery near the urethra that results irregular areas of scarring around the urethra and abnormal anatomical angulation of the urethra and the instant invention""s unique construction design allows for the positioning accommodation of anatomical variance/distortion. In so doing, the tubular knit mesh pubovaginal sling further conforms to the anatomy of the urethra and anterior vaginal wall which is an important structural feature when the anatomy of the patient is distorted by urethral prolapse or previous vaginal surgery around the urethra.
Since normal women have a bladder neck sphincteric continence site and a mid-urethra sphincteric continence site, a wide tubular mesh sling design is disclosed that anatomically supports both sphincteric continence sites. The proximal part of the wide sling segment is positioned slightly above the bladder neck and the distal part of the wide sling segment is positioned slightly below the mid-urethra. The dual urethral continence site structure of the tubular knit mesh sling provides a significant continence advantage compared with other incontinence designs.
The instrument used for sling transfer has a reverse curve tip that is specifically designed to slide along the posterior surface of the pubic bone. It is designed to push the bladder away from the pubic bone and decrease the incidence of bladder perforation and pelvic organ injury resulting from sling transfer instrument placement.
The suprapubic sling transfer instrument is passed through the anterior abdominal wall to the anterior margin of the pubic bone. After passing through the anterior abdominal wall, the sling transfer instrument is passed directly over the upper edge of the pubic bone and the handle is rotated sharply upward to direct the reverse curve tip along the posterior surface of the pubic bone. As the tip is passed along the back of the pubic bone toward the lateral attachments of the vagina, any anatomical structures adhering to the pubic bone are pushed away by the reverse curve tip of the sling transfer instrument. This design modification is especially important in women who have had previous pelvic surgery and have anatomical structures adhering to the pubic bone because of scar tissue due to the previous surgery.
To position the sling, a 3.5 cm midline anterior vaginal incision is made that extends through the vaginal mucosa. The vaginal mucosa is separated away from the vaginal wall laterally to the pubic bone. The tip of the sling transfer instrument perforates the vaginal wall in the lateral part of the dissection. The sling transfer collar is placed on the sling transfer instrument. The sling transfer instrument is used to transfer the end of the sling to the suprapubic area on both the right and left sides. The center suture is used to position the sling in the center of the urethra and the suture is removed. The sling spacer is placed under the sling and the sling tension is adjusted. The tip of the sling is cut on each end and the plastic sheath is removed on each side. The sling spacer is removed and the excess sling is cut at the skin level in the suprapubic area. The vaginal mucosa is closed and a vaginal pack and Foley catheter are placed.
When transvaginal placement of the instrument is preferred, a transvaginal sling transfer instrument having the same design features as the suprapubic transfer instrument is used. The transvaginal sling transfer instrument is passed from the vagina along the posterior surface of the pubic bone to the suprapubic area. A semilunar transverse incision in the anterior vaginal wall is recommended for the transvaginal approach to allow the sling transfer instrument to be introduced from an anatomically lateral vaginal position. The sling transfer instrument needs to be introduced into the retropubic space from the lateral margin of the vagina. The transverse incision allows the tip of the sling transfer instrument to be placed against the posterior side of the pubic bone at the lateral margin of the vagina. From the lateral margin of the vagina, the sling transfer instrument can be passed in a straight line through the retropubic space against the posterior surface of the pubic bone to the suprapubic area. Once the sling transfer instrument on each side is passed through the retropubic space, the detachable tip of the sling transfer instrument is disconnected from the shaft of the sling transfer instrument and the sling transfer instrument is removed leaving the semi-rigid plastic sheath for transfer of the tubular mesh sling through the retropubic space to the suprapubic area.
In another readily envisioned embodiment, the tubular knit mesh sling is shaped to fit transvaginal placement using bone anchors, tissue anchors, and conventional sutures. The tubular mesh design can be fitted for cystocele repair, rectocele repair, and to anatomically support other tissues in the body. The disclosure of this structure applies to all tubular sling designs and includes but is not limited to all tubular knit or woven patterns. The material used in construction of the tubular sling includes all biocompatible synthetic polymers both biodegradeable and non-biodegradeable. The disclosure includes materials used in construction of a tubular sling composed of any organic or inorganic compound used singularly or in combination to produce an implantable tubular design used for anatomical support. The tubular sling design used for urethral and vaginal support is disclosed to contain tissue remodeling materials within the center segment when clinically indicated. Biodegradable tubular mesh sling may contain tissue remodeling materials including but not limited to homologous dermis, heterologous dermis, and porcine intestinal submucosa.
Given the deficiencies of the contemporary art and the enhancement teachings of the instant invention, it is an object of the instant invention to provide a tubular mesh sling for incontinence which eliminates urethral obstruction and wetting difficulties associated with slings and tapes of the contemporary art.
It is another object of the instant invention to provide an incontinence solution which avoids the morbidity associated with rectus fascia tissue transplanted from the abdomen to the vagina of a patient and the long term durability deficiencies of cadaveric tissue as used in the contemporary art.
It is a further object of the instant invention to provide an incontinence solution which avoids the numerous and serious complications from intra-operative injury to organs in the pelvis.
It is yet another object of the instant invention to avoid paravaginal dissection required of surgical instruments and methodologies associated with the contemporary art.
A further object of the instant invention is to provide an incontinence solution which is embodied as a sling design capable of conforming to the anatomical variations of the urethra of women who have urinary incontinence.
Yet another object of the instant invention is to disclose an incontinence solution by providing a tubular knit mesh pubovaginal sling and be rolled to the desired position along the urethra.
A yet further object of the instant invention is to provide a tubular knit mesh pubovaginal sling which conforms to the anatomy of the urethra and anterior vaginal wall when the anatomy of a patient is distorted by urethra prolapse or previous vaginal surgery.
Another object of the instant invention is to provide a two-layer tubular mesh sling in a single component structure that has an anterior surface which attaches to the vaginal wall adjacent to the urethra and a posterior surface which attaches to the vaginal mucosa.
An additional object of the instant invention is to provide an incontinence solution in a tubular mesh sling form which avoids buckling due to opposing forces of the vaginal wall and vaginal mucosa on the sling.
A further object of the instant invention is to provide a tubular mesh sling which has an anterior and posterioral layer which provides greater tensile strength compared to tape mesh slings of the contemporary art.
Yet another object of the instant invention is to provide a tubular mesh sling design which demonstrates a significant degree of elasticity of the sling material.
A further object of the instant invention is to provide a tubular mesh sling which embodies a dual continence design and can be positioned to support both the mid-urethra and bladder neck sphincteric continence sites.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated herein by reference, and which constitute a part of this specification, illustrate certain embodiments of the invention and, together with the detailed description, serve to explain the principles of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the design engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in this application to the details of construction and to the arrangement so the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.